Tire building drum



July 4, 1950 H. D. STEVENS ETAL TIRE BUILDING DRUM 4 Sheets-Sheet 1 Filed Feb. 26, 1947 I NV 5 N TORS HORACE D.5TE.VEN5 AND y 1950 H. D. STEVENS ETAL 2,514,215

TIRE BUILDING DRUM Filed Feb. 26, 1947 4 Sheets-Sheet 2 I NVEN'IORS HORACE D. STEVENS AND RAYMOgW. ALLEN ATTORNEYS y 1950 H. D. ST EVENS ETAL 2,514,215

TIRE BUILDING DRUM Filed Feb. 26, 1947 4 Sheets-Sheet 3 I N v e: N TORS HORACE. DSTEVENS AND RAYMOND W.ALLEN ATTORNEYS July 4, 1950 H. D. STEVENS ETAL TIRE BUILDING DRUM 4 Sheets-Sheet 4 Filed Feb. 26, 1947 7 Al/ III/II/I/I/I/III/ //III/IIIIIIIIII/IIIIIIIIII/IIIII/W IN VENTORS m I V v EL L a N no 0 D N O A 3 0A Q Patented-July 4.1950

TIRE BUILDING DRUM Horace D. Stevens and Raymond W. Allen, Akron,

Ohio, assignors to The Firestone Tire & Rubben Company, Akron, Ohio, a corporation of Ohio Application February 26, 19;, Serial No. 730,996

7 Claims.

This invention relates to tire building forms or drums such as commonly are employed in the manufacture of pneumatic tire casings, and more especially it relates to improved collapsible tire building drums.

The problem of providing superior collapsible building drums has long been present in the tire manufacturing industry, and many expedients have been proposed as the solution thereof. Some collapsible tire building drums comprise key sections and intermediate sections, the latter being collapsible after the key sections have been collapsed. Such drums require the use of a large number of elements of different sizes and shapes, thus making for increased weight and cost. Furthermore the groups of sections require to be collapsed and expanded in succession, thereby consuming time. Many types of collapsible drums collapse to non-circular form, that is, to somewhat elliptical shape. In such drums the long axis of the collapsed drum is greater than the inside diameter of the tire beads of a tire built thereon, with the result that the finished tire must be deformed out of round to remove it from the drum, and the inside bead core of the succeeding tire to be built upon the drum must be deformed to pass it over the drum so that it may be mounted upon the inner bead ring. Itis to the avoiding of the foregoing and other disadvantages of prior art constructions that the present invention primarily is directed.

The chief objects of the invention are to provide a collapsible tire building drum that is light in weight; and which assumes a substantially circular shape when collapsed. Another object is to provide a drum of the character mentioned whereof the several collapsible sections are of identical size and shape. Other objects will be manifest as the description proceeds.

Of the accompanying drawings:

Fig. 1 is a side elevation .of ,a collapsible tire building drum embodying .the invention, and a portion of a pneumatic tire built thereon, other elements of the associatedtir'e building machine being indicated in broken lines.

"Rig. 2 is a section on the line 2-2 of Fig. 1 and Fig. 3 showing an end elevation of the tire building drum in expandedor operative position.

Fig. 3 is a longitudinal section of the drum substantially on the line 3-3 of Fig. 2.

Fig. 4 is a section similar to Fig. 2 showing the position of the various elements of the drum when in collapsed or inoperative position; and

Fig. 5 is a substantially diametric section of a drum that constitutes another embodiment of the invention.

that shown in broken lines.

Referring to the drawings, particularly Fig. 1. thereof, there is shown a collapsible tire building drum generically designated ill, a fragmentary tire casing i I being shown as it appears when built on said drum. The drum may be used on any conventional tire building machine such as Said tire building machine comprises the usual housing [2 in which is located the motor (not shown) for driving the drum, there being a tubular sleeve l3 extending laterally from the housing, which sleeve encloses a driven quill or spindle I8 that supports and rotates the drum, and which is connected thereto in a manner presently to be explained. The spindle I8 is provided at its end remote from the drum with a driving pulley 85 connected by transmission belts It with the motor aforementioned. The inner bead-setting ring M of the machine is mounted on the sleeve l3 for axial movement thereon, in the usual manner. Various mechanisms for applying the constituent parts of the tire H to the drum in are indicated generally by the numeral l1. Said mechanisms are substantially similar to those employed with the tire building machine shown in U. S. Patent Number 2,381,379,. issued August '7, 1945 to H. D. Stevens, one of the co-inventors herewith.

As shown in Fig. 3, the quill or spindle I8 is hollow or tubular, and is formed with an integral flange or collar 20. The drum I0 includes a hub portion l9 that is mounted upon the spindle l8 and has its rear end in abutting relation to said flange 20, the forward end portion of said hub projecting beyond "the extremity of said spindle. A thrust bearing 2| is located between the rear face of the flange 20 and the outer end of sleeve l3, and a journal bearing 22 is positioned between the sleeve 13 and the spindle I8, adjacent said flange 20. The spindle l8. and hub l9 are connected to each other for concurrent rotation by means of a conventional key 25. Extending axially through the hollow quill or spindle I8 is a shaft 23 that has a region 23a of reduced diameter near its outer end, which portion is received in a bearing 24 mounted in the outer extremity of hub 19, beyond spindle l8. Beyond reduced portion 234 the shaft 23 has a further reduced portion 23b upon which a disc or wrist plate 48 is mounted, the latter having driving connection with the shaft through the agency of key 48. Lock nuts 41 on the end of shaft 23 retain the shaft 23, bearing 24, and wrist plate 48 in assembled relation.

The arrangement is such that the shaft 23 may be oscillated relatively of spindle I8 with the result that wrist plate 48 is oscillated relatively of dition.

drum-hub l9, such relative movement being utilized for effecting the collapsing and expanding of the drum it, as subsequently will be explained. For Oscillating the shaft 23 relatively of the spindle l8, any suitable manually operated or poweroperated means may be employed. Solely for illustrative purposes, power-operated means for this purpose is indicated in Fig. 1, said means comprising a pinion 60 mounted upon the shaft 23 at the rear end thereof. a pair of racks 3i meshed with said pinion at opposite sides thereof, and fluid pressure operated cylinders 32 for reciprocating the respective racks, said cylinders being mounted upon the pulley l8. Charging oi the outer ends of cylinders 62 will oscillate the shaft 23 the proper angular distance to eilect collapse of the drum Ill. The procedure is reversed to restore the drum to expanded operative con- Although the cylinders 62 may be utilized to collapse and expand the drum while rotating, such operations preferably are eflected while the drum is stationary.

The hub i3 is formed with a plurality of radially extending lug or cars 33, 23, which ears are arranged in pairs, the ears of each pair being spaced apart from each other axially of the hub and connected to each other by an integral web 29. As shown, there are five pairs of the ears 23, the same being disposed symmetrically around the hub. Supported in the outer, ends of each pair of ears 28 are respective hinge, pins 30, which pins preferably are non-rotatlve with respect to the ears, and are disposed parallel to the axis of the drum. The opposite end portions of each pin 30 extend beyond the outer lateral faces of the ears 28 that carry the pin, the projecting portions of the pin being provided with respective roller bearings 31 upon which are journaled respective, elongate, slightly arcuate arms 32 that extend non-radially from their pivots and have their free ends integrally united with a rectangular saddle-plate 33 adjacent the margin of one o! the long sides thereof. The saddle-plates 33 are transversely arcuate, their axes of curvature being coincident with the axis of the drum in the expanded or operative condition of the latter, as shown in Fig. 2, the arms 32 extending from the concave sides thereof. The pivot pins 30 are retained in place by the usual washers and nuts 3| on the opposite ends thereof. Each saddle-plate 33 is formed with a medial, transversely extending rib 35, the function of which presently will be explained, said ribs 35 being disposed in the central transverse plane of the drum Ill.

The perimeter of the drum comprises *a pinrality of drum segments, namely, a group (five) of drum segments 330 located at the inner end of the drum and a group (five) of drum segments 33b located at the outer end of the drum. All segments 33a. are identical with each other and all segments 33b are identical with each other. The segments 33a difler from the segments at only in that the lateral marginal profiles over which the bead portions of the tire H are built are located on one side of the segments 33a and on the opposite side of segments 33b. In the expanded or operative condition of the drum the segments of each group 33a, 3312 are disposed end to end and each define a full circle of 360 degrees. The confronting ends or margins of the drum segments are complementally beveled. The drum is designed to rotate in counter-clockwise direction as viewed in Fig. 2, and the marginal beveling on the drum segments is such that the leading edge of each segment underlies the trailing edge of the preceding segment.

There is a drum segment 38a and 38bmounted upon the convex side of each saddle-plate 33, the width of each segment being such that it projects beyond the end margin of the saddle-plate axially of the drum. Each drum segment is secured to its saddle-plate by two cap screws 40, which cap screws extend through respective slots 4| in the saddle-plate and are threaded into the segment nearer the leading than the trailing end thereof, said slots ll being disposed parallel to the axis of the drum. The arrangement is such that the drum segments 38a, 381) may be adjusted toward or away from the central plane of the drum and thus to alter the length of a tire-band Ii built thereon. Additional threaded apertures 42 are formed in each drum segment to receive the screws 40, thereby increasing the extent of adjustment that may be obtained. A key 43 is interposed between each drum segment and its saddle-plate 33, in confronting keyways formed in each, to assure accurate registry of these members.

when the drum segments 38a, 381) are in their innermost positions of axial adjustment they abut the ribs 35 on the saddle plates 33. In other positions of axial adjustment the inner margins of the segments are in spaced relation to said rib, as shown in Fig. 3. To cover such spaces at each side of the ribs 35, and also to span the space between adjacent saddle plates 33 in the central circumferential region of the drum, so that the latter presents a circumferentially continuou periphery, bridge plates 45 are provided. Said plates are of relatively thin metal and are of the same length as the drum segments 38a, 33b. One plate 45 is provided for each saddle plate 33, said plate 45 being attached in its medial region to the rib 35 of said saddle plate. The bridge plates 45 overlie the drum segments 33a, 33b to the extent necessary to conceal the spaces between the segments and the ribs 35 in all positions of axial adjustment of said segments.

In the expanded or operative condition of the drum the drum segments 38a, 38b are disposed in the position of circumferential continuity shown in Fig. 2, and define a true circle. In the collapsed or inoperative conditionof the drum the said drum segments are in the positions shown in Fig. 4 wherein they are symmetrically disposed about the axis of the drum, but in overlapping relation and nearer to said axis to en- 'able the removal of the finished tire. Because of the symmetrical arrangement of the various elements of the drum as shown in Fig. 4, the drum at all times is in rotational balance, and no strains are imposed on the machine such as would be present if the drum were rotated while in unbalanced condition.

The drum is collapsed by rotary movement of th wrist plate 48 relatively of the hub l9,which relative movement is efiected by the relative movement of shaft 23 and quill or spindle It, as previously explained. To this end links 50 are pivotally connected at one end to the wristplate 43 by means of bolts 5i, and at their other ends are pivotally connected to respective pairs of arms 32 of the saddle plates 33 by pivot pins 5!. Roller bearings 53 similar to those shown at 3i are employed between the links 50 and the pivot pins 52 to reduce friction at these points. Friction material 34, Fig. 3, is employed between the links I! and wrist-plate 43, around the bolts 5|, to provide friction at these points for a purpose presently to be explained, said bolts 8! providing means whereby the amount of friction may be adjusted. At the point where each pivot pin 52 is mounted in the respective pairs of arms 32, the latter are connected by an integral tubu-' lar tie or brace 54, Fig. 3, through which brace the pivot pin extends. The arrangement is such as to strengthen the arms 32 and assure that force applied to the links 50 will be distributed to both arms of each pair thereof. It will be seen that the wrist-plate 48 and links 50 constitute toggles that are interposed between the shaft 23 and saddl plates 33, said toggles being straightened in the expanded condition of the drum shown in Fig. 2 and flexed or bent in the collapsed condition of the drum shown in Fig. 4. In the expanded condition of the drum shown in Fig. 2, the bolts 5i are located slightly past radial alignment with the axis of the drum and the respective pivot pins 52. Such overcenter movement of the toggle hinges 51 is limited by lugs 58 formed on the outwardly presented lateral faces of the respective outermost arms 32 of each pair of arms, said lugs projecting into the paths of the respective links 50 to be abutted thereby, whereby further overcenter movement of the hinge points 5! is arrested. The overcenter arrangement described assists in preventing collapse of the expanded drum from pressure applied radially to the periphery of the drum, especially during the fabrication of a tire thereon. Collapse of the drum from the aforementioned cause additionally is opposed by the friction at the hinge bolts 5! as the result of the friction material 64 located at these points.

In the operation of the invention, the collapsing and expanding of the drum is effected by angular or oscillatory movement of the wristplat 48 relatively of the drum-hub i9, which relative movement is the result of similar relative movement between the shaft 23 and the quill or spindle l8, induced by the fluid pressure operated cylinders 82 as previously explained. The arrangement is such that charging of the rear or outer ends of the cylinders 62 will oscillate the wrist-plate 48 in counter-clockwise direction, as indicated by the arrow in Fig. 4, and thus effect collapse of the drum segments. When the cylinders 62 are reversely charged the wrist-plate is turned in clockwise direction to expand the drum segments to the condition shown in Fig. 2.

Since all -of the drum segments concurrently move toward collapsed position, and such movement is non-radial with relation to the tire ii on the drum initial separation of tire and drum segments occurs at the noses or leading edges of the latter, and progresses toward the trailing edges thereof with a peeling action, the arrangeinent being such that the mold segments are stripped from the tire with but little power consumption. The drum segments are symmetrically arranged when collapsed which arrangement is advantageous if the drum is expanded or collapsed while rotating; however, it is preferred that such expansion and collapse of the drum be effected while it is stationary. Furthermore, the symmetrical arrangement of the collapsed drum facilitates the removal of the finished tire ll therefrom, especially if such re-' moval is eflected by mechanical means. Due to the use of many identical elements, the drum may be manufactured at relatively low cost. The drum is light in weight and achieves the other advantages set out. in the foregoing statement.

' chiefly in the location of the wrist-plate and the mechanism for oscillating the same relatively of the drum-hub. The drum, generically designated 10, is supported and rotated by the usual power driven spindle II, the latter having an outer end portion 12 of reduced diameter to provide a shoulder 18 on the spindle. The drum I0 comprises a hub 14 that is mounted upon the reduced portion I2 of the spindle and has driving engagement therewith through the agency of a key 15. A cap plate 16 is secured upon the outer extremity of the spindle by an axial cap screw l1, said cap extending over the adjacent end of the hub 14 to retain the latter on the spindle, the opposite end of the hub abutting the shoulder I3 of the spindle.

The end portion of hub 14 that abuts shoulder 13 is slightly reduced in diameter, and mounted upon such reduced portion of the hub is an annular bearing bushing 80 upon which a wristplate 8| is journalled. The latter is formed with a tubular axial extension 82 that extends rearwardly over the spindle l I, to the left of shoulder 13 as viewed in Fig. 1, the arrangement being such that the wrist-plate and its extrusion may be oscillated relatively of the spindle II and the hub 14. For so oscillating the wrist-plate, the extension 82 thereof has driving connection, through the agency of keys 83, with one end of a tubular sleeve 84 within which the spindle H is located. The extension 82 supports one end of the sleeve 84, the other end of which (not shown) is journalled on the spindle 'H in any suitable or desired manner. The arrangement is such that the sleeve 84 will rotate with the spindle ll whenever the latter is driven, but is capable of angular or oscillatory movement relatively For so oscillating the sleeve 84, any

thereof. suitable manually operable means (not shown) may be provided, which means preferably is operable when the spindle H is stationary to obviate sudden collapsing of the drum and strains incidental thereto.

The relative oscillatory movement of the wristplate' 8| and hub 14 is utilized to effect collapse and subsequent expansion of the drum l8 and to this end a plurality of links 81 are pivotally connected at 89 to collapsible elements of the drum structure. Each pivotal connection 88 includes friction material 98, the latter being identical in structure and function with the friction material 84 of the previously described embodiment of the invention, and the links 81 being identical with the links 50 thereof. All other elements of the drum structure are identical with similar elements of the previously described embodiment of the invention, wherefore a more detailed description thereof is thought not to be necessary.

The modified embodiment of the invention includes all of the advantageous features of the first-described embodiment thereof.

Other modifications may be resorted to without departing from the spirit of the invention, or the scope thereof as defined .by the appended claims.

What is claimed is:

1. A rotary tire building form comprising a ment, arms fixedly connected to each segment intermediate the ends thereof, said arms extending non-radially of the hub and pivotally connected to the latter, a wrist plate disposed coaxially of the hub and capable of oscillatory movement relatively thereof, and links pivotally connected to said wrist-plate and to the respective arms, intermediate the ends of the latter and at a fixed point thereof, for effecting collapse or expansion of the drum upon relative oscillation of the hub and wrist plate.

2. A combination as defined in claim 1 including stop-lugs formed on the respective pairs of arms adapted to arrest movement of the links during expansion of the drum in a position wherein the pivot points of the arms on the wristplate' are slightly over center with relation to radial lines extending from the pivotal connections between arms and links to the axis of the drum.

3. A combination as defined in claim 1 including means creating friction between the wristplate and the arms that are pivotally connected thereto.

4. A collapsible tire building drum of the character described comprising a plurality of segments formingthe drum periphery, a rotary spindle upon which the drum is indirectly mounted. a hub mounted on said spindle, arms extendin'g'between said hub and said segments, one end of each of said arms being pivotally attached directly to said hub and the other end of said arms being permanently bolted to said segments at points nearer the leading than the trailing ends of the latter, a rotary shaft extending axially through said spindle and being rotatable independently thereof, link attachment means mounted on and rotatable with said shaft, links pivotally connected to said means and to said arms, intermediate the ends of the latter, for effective collapse and expansion of the drum periphery upon relative movement of the hub and link attachment means.

5. A rotary tire building drum comprising a driven hollow spindle upon which the drum is mounted and by which the drum is driven, a rotatable hub mounted on and being keyed to said spindle with said'hubs forward end projecting beyond the extremity of said spindle, a plurality of arcuate segments, arms mounting the segments on said hub, one end of each said arms being pivotally attached directly to said hub and the other ends thereof terminating in transversely slotted saddle plates formed integral therewith, said plates being fixedly attached to said segments by means of cap screws extending through said slots and in threaded relation with said segments and with the heads of said screws in contact with the radial inner surface of said plates, a shaft extending axially through said spindle and hub, a wrist plate mounted on and keyed to an end of said shaft, said shaft being rotatable independent of said spindle, links pivotally connected at one end' to said wrist plate and at their other end pivotally connected to said arms, intermediate the ends of 8 the latter, for efiectlng collapse or expansion of the drum upon relative rotational movement of the hub and wrist plate.

6. A rotary tire building drum comprising a driven hollow spindle upon which the drum is mounted and by which the drum is driven, a rotatable hub mounted on and being keyed to said spindle with said hub's forward end projecting beyond the extremity of said spindle, a plurality of arcuate segments, arms mounting the segments on said hub, one end of each said arms being pivotally attached directly to said hub and the other ends thereof terminating in transversely slotted saddle plates formed integral therewith, said plates being fixedly attached to said segments by means of cap screws extending through said slots and in threaded relation with said segments and with the heads of said screws in contact with the radial inner surface of said plates, a shaft extending axially through said spindle and hub, a' wrist plate mounted on and keyed to an end of said shaft, said shaft being rotatable independent of said spindle, links pivotally connected at one end to said wrist plate and at their other end pivotally connected to said arms, intermediate the ends of the latter, for eifecting collapse or expansion of the drum upon relative rotational movement of the hub and wrist plate, the center point of said connection of said link to the wrist plate being at a point slightly past radial alignment with the axis of the drum and the center of said connections to said arms.

7. A rotary tire building form comprising a hub mountable upon a rotary spindle, a plurality of arcuate segments collectively constituting a complete cylindrical drum periphery, drum mounting arms having one end of each aflixed to said segments and the other end pivotally connected to the hub, said spindle having link attachment means afilxed thereto normally rotating with said hub and capable of independent movement relatively to the hub, and a plurality of links each having one end pivoted to a said drum mounting arm, intermediately of the ends of the latter, the other end of each of said links being pivoted to said link attachment means, whereby said segments are'concurrently drawn circumferentially and radially inwardly to efiect collapse of the drum with the segments in overlapping relation as a result of such relative movement in' one direction of rotation of said spindle with respect to said hub and are concurrently expanded to cylindrical drum form as a result of relative movement in the opposite direction of rotation of said spindle with respect to said hub.

HORACE D. STEVENS. RAYMOND W. ALLEN.

REFERENCES o l'rnn The following references are of record in the file of this patent:

UNITED STATES I PATENTS Number Name Date 905,305 Gage Dec. 1, 1908 2,201,469 Bostwick May 21, 1940 Certificate of Correction Patent No. 2,514,215 July 4,1950 HORACE D. STEVENS ET AL.

It is herebv certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 7, line 11 after the word plate and before the period insert the center point of sazd connection to the wrist plate being at a point slightly past radial alignment with the am's of the drum and the centers of said cannectz'ons to said arms; and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oifice.

Signed and sealed this 20th day of March, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

